1. Field of the Invention
The present invention relates generally to systems and methods for prolonging the life of a memory, and especially to a data structure design system and method for prolonging the life of an FRAM (Ferroelectric Random Access Memory).
2. Description of the Related Art
In recent years, a memory has been a very important part of a data storage apparatus, especially an electric memory. Typical electric memories include RAMs (Random Access Memories) and ROMs (Read Only Memories). Although the read/write speed of a RAM is less than 100 nanoseconds, it cannot perpetually store data. A ROM can perpetually store data; however, its read/write speed is more than a microsecond. These electric memories cannot simultaneously have the two described advantages. Then the FRAM was developed. It has a very fast read/write speed, and can retain data in a power-off state.
The art of FRAM storage has been described in publications such as U.S. Pat. No. 6,385,078, entitled “Ferroelectric Random Access Memory (FRAM) Device and Method for Controlling Read/Write Operations Thereof”, and issued on Apr. 7, 2002. In the disclosed FRAM device, an address transition detection circuit generates a pulse signal in response to a transition of a row address latched in an address latch circuit; a flat signal generating circuit generates a chip enable flag in response to an external chip enable signal; a delay circuit delays the pulse signal for a predetermined time; and after the external chip enable signal is enabled, a controller controls a row decoder circuit in a disabled state when the external chip enable signal is disabled during a delay time of the delay circuit, and controls the flag signal generating circuit to disable the chip enable flag signal.
Although the device described above can control read/write operations of the FRAM device to prevent false operations caused by noise spikes, and improve the reliability of the FRAM device, it cannot uniformly use the whole FRAM to store data. Instead, the FRAM always stores data in a critical area. Thus when the FRAM has been used repeatedly, it is liable to wear out and become inoperable. Accordingly, what is needed is a data structure design system and method which can overcome the above-described problems and prolong the life of an FRAM.